1. Field of the Invention
The present invention relates to a machine tool having a working space in which a receptacle for workpieces to be machined, which are exchanged after completion of a machining process, is provided.
2. Related Prior Art
Machine tools of this kind are known from the related art.
The known machine tools generally have cover panels by means of which the working space is closed off from the outside, in order to protect the environment and operating personnel from flying chips and cutting fluid. Provided in the cover panels is an opening, which can be closed off by an operator door, through which the workpieces to be machined are exchanged with already machined workpieces.
The known machine tools generally have a workpiece table on which a receptacle is provided for clamping the workpieces to be machined. When a machining process is complete, the operator door is opened either automatically or by an operator, the receptacle being opened either automatically or by manipulations on the part of the operator so that the workpiece can be removed.
The operator then first cleans the workpiece, still located on the receptacle, using a manually operated spray gun, and then removes it from the working space. Chips are then cleaned off the receptacle by the operator before a new workpiece is then, in a third operation, placed on the receptacle.
The operator must therefore reach into the working space a total of three times in order to exchange a workpiece. These operations are not only physically strenuous, but are also associated with considerable soiling, since the flushed workpiece must be removed by the operator directly from the receptacle and taken out of the working space. This results in soiling not only of the operator but also of the environment outside the machine tool, due to drips of cutting fluid.
In addition to physical exertion and soiling, a further disadvantage with machine tools of this kind is the fact that the aforementioned three operations are necessary in order to exchange a machined workpiece with a workpiece that is yet to be machined. Since these three manipulations are performed by hand, they constitute the speed-limiting step in determining workpiece-to-workpiece time. In the case of piecework in particular, this additionally places the operator under severe performance pressure, so that errors and negligence are unavoidable, especially in cleaning the workpiece and the receptacle.
A further disadvantage thus results because of manual operation in that when receptacles are not completely cleaned, remaining chips, for example, can prevent the newly clamped-in workpiece from sitting correctly in the receptacle, so that deviations in machining accuracy occur.
Some of these disadvantages can be avoided by using automatic workpiece changing mechanisms, although these are associated with a whole series of disadvantages. In addition to the very high cost factor, these workpiece changing mechanisms also constitute a disadvantage in that they require highly qualified personnel, the acceptance of these highly automated machine tools being, in practice, relatively low.
A further disadvantage with automatic workpiece changers lies in the fact that said workpiece changers operate through the usual operator door, so that in the event of maintenance work on the machine tool, there is not only the danger of collisions with the workpiece changing mechanism, but the accessibility of the working space is also considerably degraded by such mechanisms.